A solar charge controller is a device that prevents your solar inverter batteries from overcharging. It also monitors current and voltage levels that are radiated from a solar panel to the battery. This is an important element of your solar panel system as it prevents deep cycle batteries from overcharging and no energy supply is allowed to return to solar panels at night.
Let’s try to understand the functions of a solar charge controller in detail.
(Image Source- Luminous)
Prevents reverse current at night.
At night, the batteries in solar inverters can conduct small amounts of electricity to the solar modules. This can be very dangerous as it can drain the battery and damage the entire solar panel system. A solar charge controller does not allow this and protects your system.
Avoid overcharging the batteries.
Once your solar inverter’s battery is fully charged, it cannot accumulate any more incoming power. It is important that no more current gets into the battery after a full charge. A solar charge controller interrupts the current flow as soon as the battery reaches a certain voltage, thus preventing overcharging.
There are two types of Solar Charge Controllers available in the Indian market
Pulse width modulation (PWM)
The charge controller with pulse width modulation works by connecting the solar system to the battery bank in order to prevent the battery from being overcharged. During bulk charging, there is a free flow connection between the bank battery and the array. When the battery is fully charged, its voltage increases, which also increases the solar panel voltage.
MPPT Controllers
Maximum Power Point Tracking (MPPT) works in a more advanced way. These controllers can easily read input current and voltage levels from the photovoltaic field and can be adjusted appropriately. This helps you in identifying the ideal operating voltage and setting it up accordingly. This allows the controllers to generate maximum power. MPPT controllers can also be used with higher voltage PV arrays without any problems.
Which solar charge controller should you buy?
While MPPT technology is available at slightly higher prices than PWM, both are equally capable of doing the job, but which of these controllers is better for you will depend on your location and use. Make sure not to exceed the input voltage that the controller can accept. You should choose the controller based on your voltage requirements. In addition to these factors, temperature and open circuit voltage should also be taken into account when purchasing a solar charge controller. Since the photovoltaic open circuit voltage (Voc) increases as soon as the outside temperature drops, you need to make sure that the input voltage values of your controller are ideal even for the coldest months. It’s also a good idea to choose solar charge controllers that will allow you to charge your DC devices without an adapter.
A good example of this type of controller is the Luminous Solar Charge Controller. This controller has an integrated USB port. You can charge your phone and other devices directly through this connector without using additional power. This controller works on two battery voltages: 12V and 24V and can vary depending on your requirement.
Regardless of which controller you buy, it is advisable to take into account your application, budget and location. Moreover, you must go for reputable brands like Luminous that offer a range of solar charge controllers with many innovative features.